This invention relates to yard hydrants, and more particularly to yard hydrants which resist freeze-up in cold weather while keeping ground water and other contaminants from commingling with the fluid pumped through the hydrant.
Freezeless yard hydrants are old in the art, and conventionally have a drain release valve in the bottom portion thereof which is located below the frost line, and which opens when the main hydrant valve is closed. Thus, when this takes place, water ceases to flow from the fluid outlet above the ground surface, and water within the hydrant drains therefrom into the surrounding soil or rock bed adjacent the drain release valve below the frost line. While this system works well to solve the chance of water freezing within the hydrant, some danger exists that contaminated outside water might enter the hydrant.
Some attempts have been made to solve this problem by using a reservoir around the hydrant below the frost line, which will collect residual water in the hydrant when it is shut off. However, units are apt to fill and overflow the reservoir when a hose is attached to the hydrant. However, such existing designs do not adapt themselves for use with conventional yard hydrant structures.
With the increased public concern over the effects of pecticides and other pollutants on ground water, there is a need for a valve which isolates the reservoir fluid from surrounding ground water. There is a need for a simple, reliable valve that does not require heating by electricity or other means and will resist freeze-up during normal winter conditions without allowing contamination.
Therefore, a principal object of this invention is to provide a conventional ground hydrant structure in combination with a surrounding reservoir, wherein residual water in the hydrant is directed to the reservoir when the hydrant is closed to flow, and where water in the reservoir is removed therefrom during flow conditions by means of a venturi and check valve means.
A further object of the present invention is to provide a sanitary yard hydrant resistant to freezing and contamination.
Another object of the present invention is to provide a sanitary yard hydrant which has a check valve in conjunction with a reservoir to prevent flow of water from below the check valve into the reservoir under reduced flow conditions.
A further object of the invention is to provide a combination hydrant and reservoir wherein the hydrant can be removed from the reservoir without removing the reservoir from the ground.